Total dose effects in composite nitride-oxide films

Total dose effects in composite nitride-oxide (NO) films with nitride thicknesses from 58 nm to 183 nm and oxide thicknesses from 5 nm to 30 nm are studied. A model is proposed in order to relate the threshold-voltage shift to the NO thickness combinations. It is found that the electron-hole pairs generated in the bulk of the nitride do not contribute significantly to shifting the threshold-voltage. The NO films with 10 nm oxide show smaller threshold-voltage shift than composite films with any other oxide thicknesses.